Is there a good reason why searching for "~else" in both local raco docs and on docs.racket-lang.org does not produce any results? If this is an easy pull request I'll make it.
Rhombus ~else is a keyword, not a bound identifier like Racket else. Indexing it should be a matter of as_index, but I think we may want something like indexed_rhombus akin to indexed-racket. Should we point the index to cond or match, or to the the guide section on conditionals?
I think either cond or match would be fine; I think the key piece of information is that it's a keyword, and it's used to indicate an exceptional final clause.